Punctuated Equilibria
by bite-or-avoid
Summary: Part 4/4- She finds that she’s actually quite good at popping her heart into overdrive after all. Now complete!
1. Chapter 1

**Title**: Punctuated Equilibria

**Author**: Anna (bite_or_avoid)

**Pairing**: Booth/Brennan

**Rating**: PG-13

**Disclaimer**: I do not own them. Although having my very own Seeley Booth would be nice :-)

**Spoilers**: None explicitly. Does make reference to several episodes, including The Critic in the Cabernet

Punctuated equilibrium is a theory in evolutionary biology which states that most sexually reproducing species will experience little evolutionary change for most of their geological history (in an extended state called _stasis_). When evolution occurs, it is localized in rare, rapid events of branching speciation. It has also played a role in social and political theory, particularly in policy studies. Theories based on this concept generally attempt to explain patterns of change where periods of "stasis" are punctuated by brief and intense periods of "radical" change. (Thank you wikipedia)

* * *

**Punctuated Equilibria**

1.

The first time is an accident.

Night. Stakeout.

A Chevy Impala replaces his Sequoia, and he doesn't like it. He doesn't like any of this. The feeling of wrongness that's been niggling at the back of his brain ever since this damn case started combines with the feeling of being entirely too close to her for far too many hours. It sets his teeth on edge.

His eyes narrow as he scans the darkened street, gaze trained by years of stalking prey through a rifle's scope. But his focus as of late leaves something to be desired; he has become increasingly aware of her presence. It is a distraction he cannot afford, for her sake if not for his own, so he makes every attempt to drown out the effects of her proximity.

It's all _natural biological urges_ with her anyway.

She pokes his arm gently. His jaw clenches as something in the pit of his stomach tumbles over.

"This is completely irrational, Booth."

For some reason, it relaxes him. They're still _them_, and the way her mind works sometimes is still a mystery. This is familiar, replacing the strange new tango of the last few months.

He chuckles, eyes still scanning the shadows.

"You're gonna need to be a little more specific."

She sighs, as if explaining something very simple to a very small child. It has long since ceased to bother him.

"I believe we are wasting our time. It would be completely illogical for Mallory to come back here knowing the place has been discovered. He has, in all probability, pulled up sticks and sought out a new location."

"Stakes. Pulled up stakes, Bones. And it isn't about logic. He's _connected _to this place. He can't just abandon it."

"That's ridiculous. We're talking about his survival."

"He won't see it that way. Mallory feels like he needs to be here. I guarantee you that if we dig deep enough, we'll find a history there."

"That sounds suspiciously like psychology."

The statement sounds suspiciously like a pout, and his focus is completely shattered. He turns to face her, only to find that's she was apparently leaning over his shoulder and is now mere inches away. Way, way too close. Not close enough.

"It's not psychology. It's a feeling. I'm the gut guy, remember?"

He does his best impression of a confident grin.

She shakes her head slightly, but says nothing. She has long since learned that his gut is sometimes more accurate than her logic. And, as stimulating as arguing with him can be, she finds that being close enough to feel his breath on her face is more stimulating still. Her tongue darts out to wet her lips on impulse, and she wonders whether it would offend his Catholic sensibilities if she were to press her mouth to his own. All in the spirit of scientific inquiry, of course.

She is still considering this when a blast, like the discharge of a weapon, cuts through the stillness. She startles and leans forward, even as he lunges instinctively to shield her body with his. But they are far, far too close, and their heads bob together, their lips brushing in the slightest caress. And it's a blast of an entirely different sort, tearing through her disconcerted senses, stoking the embers of a desire that has only recently come to her attention.

He pulls away as if singed, shock rolling off him in waves, and opens his mouth to speak. But in the next instant, he's out of the car and running, and she can only assume that he is chasing after their suspect because running from her would be ridiculous. There is no pause to think as she takes off after him, long legs pounding the pavement in pursuit.

***

Later, when the suspect is in custody and they're both still too wired to go home and sleep, they'll sit in their booth at the diner and steal glances over cups of coffee.

She'll never make fun of his gut again.

He'll never forget the feel of her lips.

* * *

**Reviews are much appreciated :-)  
**


	2. Chapter 2

**Disclaimer**: I own nothing. Unfortunately.

* * *

2.

The second time is circumstance.

Connecticut. Undercover.

_Hank and Eleanor Woodchuck_ replace _Booth and Brennan_, and she doesn't like it. She doesn't like any of this. The feeling of wrongness that's been niggling at the back of her brain ever since this case started combines with the feeling of being entirely too close to him for far too many hours. It sets her teeth on edge.

She is a housewife to his investment banker; it is oppressive and demeaning and _desperate_. When she mentions this, he laughs, but she doesn't understand what is so funny. He smiles cheekily, his gaze tender and reassuring.

"It's all an act, right? Just think of us as Mulder and Scully."

She doesn't know what that means, but refrains from saying so. She steps behind the changing curtain to get ready for dinner, brain and tongue already jumping ahead.

"Why does the FBI insist on giving us ridiculous names?"

He laughs again, shaking his head as he slips into a fresh shirt.

"Next time, I'll ask if we can pick our own, _Roxie_."

She can't explain why, but she feels her cheeks flush.

***

He is waiting downstairs when she emerges ten minutes later, complaining that her gun won't fit in her purse, and he nearly jumps out of his skin. The dress is lovely, and elegant, and probably cost more than he makes in a month, and she's talking a mile a minute and he can't _breathe _dammit, because all he can think of is how that creamy skin would feel beneath his fingertips. He's not a suburban banker and she's not the little missus, but for a second the completely insane desire for it to be true floods him. He tells himself to get a grip and wishes he had the Cocky belt buckle to reaffirm reality.

Her eyes, those oceans of unfathomable blue rimmed in smoky gray, fix on him earnestly.

"Booth, are you alright?"

"You look beautiful, Bones."

It's much more of a strangled whisper than he would have liked. But she smiles, almost shyly (which startles the heck out of him), and his hand gravitates to her back as he follows her out the door.

***

Dinner goes well, considering the host is a potential murderer and the guests potential accomplices. It's the type of showy bourgeois crap he usually detests, but having Bones pretend to be in love with him makes up for it completely. He tells himself that it's actually a lot less twisted than it sounds.

She doesn't get the complexities of social niceties but, much to his amazement, she adopts her writer persona and circulates the room like a pro. If he's honest, he can admit that she charms the pants off every guy in the room. No, really. He maneuvers her away before any of them have a chance to literally strip off their pants and challenge each other to duels for her honor.

***

They search the rooms thoroughly and systematically. The study is the last room at the end of a long hall, and it smells of oak and leather. They rifle through the desk and cabinets and come away empty- handed. Suddenly, his eyes go wide in the darkened space, illuminated only by moonlight streaming in through the bay windows. For a moment, he is deathly still, and she strains to hear what has captured his attention beyond the din of laughter and conversation floating in from downstairs. But he is already in motion, crushing her body to his roughly.

She has time for only a surprised gasp before his mouth consumes hers, frenzied and possessive, and she responds with an intensity that shocks her to the core. His fingers slip beneath the neckline of her dress as his tongue slips into her mouth. No one has ever tasted her like this, touched her like this, she thinks, even though the thought is completely illogical. Vaguely, as if through a thick fog, she hears footsteps, but can't distinguish them from the blood pounding in her ears. She clutches handfuls of his hair, arching into him. He thrusts his leg between hers and pulls her closer. She can distinctly feel his firm length grinding against her thigh and, despite the fact that this is a normal physiologic reaction to their current situation, it is thrilling that he reacts this way _to her_. A moan reverberates through her, mingling with the creaking open of the door. Booth's hands move down, cupping her rear, engulfing her in his alpha-maleness. There comes a harsh laugh, a low whistle, and the door is closed again, accompanied by "They couldn't even wait to get home…" and retreating footsteps from the other side.

His lips linger a minute longer then they plausibly need to. Finally, he releases her, but the world is still spinning, and she places a hand on the wall to steady herself. He rubs the back of his neck and mumbles "Sorry", looking decidedly not. But his gaze never leaves hers, dark and hot and hungry, and the man in front of her is not Booth. He is Tony, or Buck, or Hank, or… perhaps simply a Booth she has never known before. Her bewildered eyes flicker to the very impressive evidence of his arousal, and he actually _smirks_, defying every possible expectation she could have had. Maybe he isn't such a prude after all.

She smirks back.

***

Later, when she emerges from the shower, she will find him asleep on the couch. She will watch the steady cadence of his breathing as he slumbers and bring a trembling hand to her lips. They will still burn.

She'll never find the words to rationalize that.

He'll dream about breaking the laws of physics.

* * *

**Reviews are much appreciated :-)**


	3. Chapter 3

**Disclaimer**: Still no ownership.

**Spoilers: **References to Aliens in a Spaceship, The Pain in the Heart, The Science in the Physicist, The Critic in the Cabernet

* * *

3.

The third time is warfare.

Wednesday. Hoover building.

Silence replaces banter as they leave Sweets' office, and he is uneasy. The feeling of wrongness is only amplified by how much this isn't _them_, and she feels entirely too far away. He wishes she would talk to him.

He nudges her with his elbow as they step out into the afternoon sunlight. She blinks up against the rays. She doesn't acknowledge him. He tries again.

"What's the matter?"

She shrugs her shoulders, and the chill she is giving off nearly turns the blood in his veins to ice. She hasn't frozen him out like this since….ever. He attempts levity. Whether she's laughing with him or laughing _at _him, he usually gets at least a smile from her.

"Come on," he prods. "I know you're mad. If you tell me what I did, I promise to get you some pie."

He attempts to punctuate this statement with a waggle of eyebrows and an arm slung loosely about her shoulders, but she flinches away from him. He flinches at how much that hurts.

"You know I don't like pie, Booth. Just take me back to the Jeffersonian."

The clipped tone strikes a nerve. She's angry, and he's getting angry because he doesn't know why.

"What the hell is going on in that _skalle_ of yours, huh, Bones?"

Her eyes narrow at his deliberate mispronunciation, and she begins to walk away.

"I'll call a cab. I have no desire to be around you right now."

That does it, and in two seconds flat, he's got his hand wrapped firmly around her wrist and is dragging her somewhere, anywhere, where they can have this out….

Apparently, that somewhere is the alley behind the Hoover building, and no sooner do they have some relative privacy than she is wrenching free of his grasp.

"Let go of me."

The fact that he's still standing proves that she's using restraint. But his is suddenly gone.

"Or what?"

He pitches his voice low, dangerous, and it's having at least some effect because her pupils enlarge ever so slightly.

"I'm not doing this, Booth."

He's so damn tired of her always being in control. Of going slow, being gentle, for her sake. Sometimes he aches so much for the vulnerability she shows him that he forgets how tough she is. How much he used to push her only to have her push back twice as hard.

He pushes now, literally and figuratively. She's pinned against the concrete wall, his broad arms on her shoulders keeping her in place. She has half a mind to kick him in the testicles, then thinks better of it. Because no matter how maddening this dangerous domineering crap is, on a very primal level, it's sexually stimulating too.

"You drive me insane, you know that? Dammit, just tell me!"

He's losing control, and she relinquishes hers.

"You almost died!"

It's an angry hiss, but her lip trembles. She shoves her palms against his chest, hard, and he's so startled that he nearly lets her go. It's the accusation in her voice he can't wrap his mind around.

Since when is one held responsible for one's own brain tumor?

But he doesn't get a word in, because now that the dam has burst there's no holding back the flood. And it's not the tumor, he realizes, but something else she's kept festering inside her for so long.

"How could you? How could you make me trust you, depend on you, and then risk yourself like that? I thought you were dead. _Because of me_. And then I find out that it was all staged. You spent all that time ingratiating yourself into my life, and then deemed that I wasn't important enough to inform of your plan. You _left_ me, Booth. You promised you wouldn't, and you did. And I hate you for that. I hate you for making me need you."

She's panting with exertion from her rant, eyes as wild as her words. She shoves him again, angry tears streaming down her flushed cheeks, and she's so damn infuriating and exasperating and stupefying and….

Before he can figure out what's happening they're waging a war of bodies and mouths against that damn wall. They're shoving against each other, tongues tangling, teeth nipping, hands groping, and it's rough and hard and animal, and not at all how he'd imagined it would happen. But it's still one of the most arousing experiences of his life, and he grinds her so hard into that wall that she'll have scrapes on her back tomorrow. His thigh presses up against her core and she gasps, and bites his lip hard enough to draw blood. Her hands are everywhere, clutching at his back, his arms, tearing out chunks of hair. Someone moans, her or him, or both- he can't be sure. His palms are hot against her breasts despite the fabric barring him from flesh, and she pushes him back far enough that she can grip him through his slacks. And suddenly something is different, and the earth shifts, and he stumbles. And he realizes what they've done.

"Bones, I…"

Her eyes are still closed when he pulls away. His mouth is suddenly dry at the sight of her: tussled hair and red cheeks and bruised lips. Her lids flutter open and she looks at him intently. The anger is gone from her gaze, replaced instead by sadness. And longing. And something else he can't quite place, or maybe is too afraid to.

He wipes the hair away from her forehead gently, running his fingers down her jaw and letting them rest against the pale stretch of neck. And he can't help himself; he kisses her swollen lips with tenderness, and wraps her in his arms.

***

They're at Founding Fathers. Neutral ground. Negotiating a peace treaty. The anger has dissipated now, but there is a whole new kind of tension stretching between them. He wishes it hadn't happened this way.

"Can we talk without you assaulting me now?"

"Technically, it was you who…" But the technicality dies on her lips, before she's even uttered it. There's really no reason to cloud the issue with who groped who. There was enough equal opportunity groping to share the blame.

He's quiet, waiting. Going slow again, gentle again, for her sake. Sometimes they push each other so hard that he forgets how vulnerable she is, and he aches for her to show him.

"When Sweets asked us to discuss…"

He nods subtly, beginning to understand. She can't bring herself to finish the sentence. But Booth is waiting for her, so she tries again.

"It's completely ridiculous, really. Individuals should not measure their happiness by the presence or absence of another. Anthropologically speaking, when a member of a tribe dies there is a period of mourning, and then life resumes as usual. It is impossible to correlate the loss of a loved one to say, the loss of a limb or---"

"Bones…" he prods gently.

She ducks her head, twists the napkin between her fingers.

"It is completely irrational to feel like a part of you is missing when it is someone else that is gone."

He lets the weight of that momentous admission settle in his heart. He can't ask for anything more than this.

"That's why they're called feelings, Bones. They're not supposed to be rational. But I know what you mean. I felt that way, when you and Hodgins---"

"You missed Hodgins?"

She's teasing now, and that makes this a rare day indeed. He laughs quietly, but knows he needs to take his own advice and give something of himself back.

"I missed _you_. I was… terrified. I don't know what I would have done if…"

He can't bear to finish the thought. Her teeth worry her lower lip as she ponders this. She has that look of intense concentration on her face that never fails to make a warm rush sweep into his chest. He rubs absently at it, wondering how much longer it will be until he's completely useless without her. The large blue orbs finally fix on him, filled with uncharacteristic uncertainty.

"Is this like the metaphorical marks people leave on each other?"

He grins, bright teeth and warm eyes and everything that inspires a biological response she can't seem to control any longer. Her breath catches when he reaches to place a large palm over her hand.

"Yeah, Bones. It's exactly like that."

***

Later, when they lie alone in their respective beds, their thoughts will stray to each other. They will remember the way her mouth impulsively pressed against his cheek before exiting the car for her doorway, and the heat of his gaze burning through her as she walked away. They will both realize that it won't be long now.

They'll never be able to redraw the line they have crossed.

They won't want to.

* * *

**This part was borne of a deep seated need to have Booth's non-death and Brennan's non-reaction to said non-death addressed on some level. Clearly, the writers don't remember that far back :-/****  
**

**Reviews are much appreciated :-)**


	4. Chapter 4

**Disclaimer**: Not mine.

* * *

4.

The fourth time is inevitability.

Evening. Guy hug.

Her apartment replaces the bar and the diner, and they both like it. There's a feeling of rightness in being here after a long, arduous case, without falling back on the old excuses of paperwork and wanting company for a meal. They're sitting entirely too close and this is a completely natural progression. It makes her feel warm inside.

But, excuse or no, the paperwork still needs to be finished, and it won't get finished anytime soon if he doesn't stop staring at her.

"What could you possibly find so interesting?"

It's the fifth time in the last hour she's admonished him. He enjoys being able to stare openly now, instead of stealing surreptitious glances at completely inappropriate times.

"Just wondering."

She glances up questioningly from the file on her lap.

"How are you handling this, Bones?"

She stiffens slightly, her entire demeanor begging him to back away. He stays firm.

"Booth---"

"Because I know how much this must have reminded you of your mother. Of what happened to her. And I want you to feel like you can tell me."

She shakes her head stubbornly. This is the last thing she needs. To tear open that wound again, expose herself to raw anguish… It is the last thing she _wants_. She doesn't need him to tell her how to grieve. Compartmentalizing has always been a sufficient coping mechanism. She's fine, really. But he's like a dog with a bone sometimes, and there's only one way she can get him to let it go. It is something she's been planning to do anyway, so now is as good a time as any.

She moves to straddle him.

"Woah, what the…"

He jumps away, clearing half the distance between the couch and the door in a second. He holds his arms out in a defensive posture. As if he needs protection from her. Her walls almost slam back down. But the cracks he's burrowed in them, the stones he's knocked loose, the nooks and crannies he's exposed in the flawed foundation allow him to navigate unscathed. She looks up at him, her feet bare, her face painfully young without a hint of makeup. She wants him. She tries to show him how much.

"Don't you want me?"

She's never said those words to a man before. Never felt this exposed, this vulnerable. A part of her still refuses to accept the weakness in her need for him. She is far too self-sufficient to allow this need to control her. Yet here she is, practically begging.

"You can't even imagine how much."

"Then why…"

"Because I can't let you use me to hide from your pain. I won't. I'm not that guy. That's not what I am to you Temperance."

It's the use of her name that does it, rips through the tattered shreds of the reigns she's kept on her emotions. He knows who she is, and sometimes she feels like he's the only one who does.

She shows him what he is to her and breaks apart in his arms.

***

"They're not really guy hugs, Booth."

Her eyes are red and puffy when she pulls away. He laughs self- consciously.

"You caught that, huh?"

Her smile is genuine. She feels more like herself now.

"Yes. Although, it helped when Sweets informed me that you told him guys don't hug."

"That'll teach me to do something nice for the kid," he grumbles, but they both know his heart isn't really in it. She meets his eyes, and for the first time feels no fear at what she sees in them.

"Thank you, Booth."

She's not thanking him for the guy hugs.

She takes his face in her hands and kisses him softly, shifting onto his lap. They're both slow and gentle this time, and she's finally caught up to him.

She finds that she's actually quite good at popping her heart into overdrive after all.

***

Morning. Breakfast.

His well-structured body replaces the empty space at her kitchen table, and that's exactly as it should be. He watches her pour two steaming mugs of coffee and admires the way her hips sway under the silk robe. She hands him a mug, then steps back to lean against the counter as she nurses her own. Her eyes are a shade he'd never experienced until last night, and he feels himself growing hard again. It's really disturbing how much power she has over him.

Her voice meanders through the lust-addled fog his brain has become.

"May we talk about this like rational adults?"

"I was hoping that we could _act_ like consenting adults instead."

He adds his charm smile for effect. She rolls her eyes.

"Don't be puerile, Booth. There are things we need to discuss."

"Wow. You sure know how to make a guy feel wanted."

She looks confused.

"I thought I made you feel sufficiently wanted when I---"

"Woah!"

He holds a hand up in alarm. If she starts _describing_ exactly how wanted she made him feel, she's gonna end up using that smart mouth for something distinctly other than talking. He already knows he won't like this conversation, but it's Bones, and he knows when to pick his battles.

"Okay, talk."

It takes her all of a tenth of a second, or the equivalent of a sip of coffee in his mouth.

"We engaged in sexual intercourse."

Coffee spews across her kitchen table.

"Geez, Bones! Don't say it like that!"

"But we did. Four times, to be exact."

He sighs, running a hand through his hair.

"I know. I was there."

She falls silent for a moment, taking a seat across from him. For the first time, she doesn't know what to do with those talented hands of hers, and they alternate between grasping her knees and wrapping across the front of her body. She can't meet his gaze, which isn't like her, and worry pricks his heart.

"You are aware that I believe monogamous relationships to be fundamentally unnatural and simply a reflection of society's antiquated and puritan social mores."

He nods tightly, not at all comfortable with where she's going with this. She still can't meet his gaze, and she's wringing her hands together in a nervous gesture he's never seen before, and _dread_ doesn't even come close to what he's feeling. But they've always been attuned to one another, even more so now, and she must sense what she's doing to him because she looks up.

And his heart slams so hard against his ribs that he's surprised it didn't rip through his chest and land on the table. She'd be quick to point out the inaccuracy in that, naturally, but it feels pretty damn accurate from where he's sitting.

Her eyes are bright with unshed tears, and she wraps her hand around his.

"I do not find this belief to be valid any longer. Not generally speaking of course, but for myself, personally, it is… unacceptable."

Her smile is radiant as he kisses her.

This time, it just _is_.

***

Later, much later, they'll still lie wrapped up in each other. They'll still be _them_. They'll forget what the hell it was that they were so afraid of, what the hell took them so long.

They'll always be the center.

They'll always hold.

_Fin._

* * *

**So, there it is. Feel free to let me know what you liked or didn't like. Constructive critism is always welcome :-)**


End file.
